MATLAB: Specifying dimensions in mat2cell

dimensionsmat2cellMATLAB

a 4 by 5 MatriX 
A =
     1     2     3     4     5
     6     7     8     9    10
    11    12    13    14    15
    16    17    18    19    20
The Mathwork example divide sA into two 2-by-3 and two 2-by-2 subarrays:
C = mat2cell(A,[2 2],[3 2])
What are the indices here in the dimension statement:
Does [2,2] refer to 2 tables w two rows each
Does [3,2] specify the first set of tables has 3 rows, the second set 2 rows.
I can't understand or see the pattern in how the dimensions are set in mat2cell
Thank you, Nancy

Best Answer

C = mat2cell(A,[2 2],[3 2])
means that numeric matrix A is to be broken up into cells.
The first row of cells is to have [2 2][1] -> 2 rows. The second row of cells is to have [2 2][2] -> 2 rows. This is a total of sum([2 2]) = 4 rows, and it is an error if A does not have that many rows.
The first column of cells is to have [3 2][1] -> 3 columns. The second column of cells is to have [3 2][2] -> 2 columns. This is a total of sum([3 2]) = 5 columns, and it is an error if A does not have that many columns.
Thus, the sizes of the entries in C will be all combinations of [2 2] with [3 2], so
{size [2, 3], size [2, 2]  -> leading 2 from the first 2 in [2 2]
 size [2, 3], size [2, 2]} -> leading 2 from the second 2 in [2 2]
Related Question